EXCHANGE 


*UG  20I9IJ 


Determination  of  the   Mean 
Declinations  of  136  Stars 

FOR  THE  EPOCH  1912.0 


A  THESIS 


PRESENTED  TO  THE  FACULTY  OF  THE  GRADUATE  SCHOOL 
OF  THE  UNIVERSITY  OF  PENNSYLVANIA 


BY 

WILLIAM   ELIJAH  ANDERSON 

IN  PARTIAL  FULFILMENT  OF  THE  REQUIREMENTS  FOR  THE 
DEGREE  OF   DOCTOR  OF   PHILOSOPHY 

PHILADELPHIA 
1913 


PHILADELPHIA 

THE  JOHN  C.  WINSTON  CO. 
1913 


Determination  of  the  Mean 
Declinations  of  136  Stars 

FOR  THE  EPOCH  1912.0 


A  THESIS 


PRESENTED  TO  THE  FACULTY  OF  THE  GRADUATE  SCHOOL 
OF  THE  UNIVERSITY  OF   PENNSYLVANIA 


BY 

WILLIAM   ELIJAH  ANDERSON 

IN  PARTIAL  FULFILMENT  OF  THE  REQUIREMENTS  FOR  THE 
DEGREE  OF   DOCTOR  OF  PHILOSOPHY 

PHILADELPHIA 
1913 


PHILADELPHIA 

THE  JOHN  C.  WINSTON  CO. 
1913 


INTRODUCTION. 

The  Wharton  Reflex  Zenith  Tube  of  the  Flower  Observa- 
tory is  an  instrument  of  somewhat  unusual  design,  but  one 
capable  of  high  accuracy  in  the  measurement  of  the  declina- 
tions of  stars.  Its  precision  for  this  purpose  arises  from  the 
fact  that  no  level  readings  enter  into  the  observations,  and 
hence  the  troublesome  and  uncertain  variations  which  are 
found  even  in  the  most  accurately  constructed  level  tubes 
cannot  with  this  instrument  produce  their  usual  anomalous 
effects.  The  excellence  of  this  particular  instrument  for 
this  special  kind  of  work  has  been  fully  demonstrated  by 
the  extensive  series  of  observations  made  with  it  by  Pro- 
fessor C.  L.  Doolittle  in  connection  with  his  researches  into 
the  variation  of  terrestrial  latitude. 

As  the  field  of  this  instrument  extends  to  but  little  farther 
than  15'  from  the  zenith,  only  those  stars  can  be  observed 
withit  whose  declinations  are  at  this  time  nearly  equal  to  the 
present  latitude  of  the  Flower  Observatory.  But  as  the  diam- 
eter of  the  objective  is  eight  inches,  all  stars  so  bright  as 
those  of  the  8.5  magnitude  can  be  well  observed,  and  it  was 
believed  that  the  accurate  determination  of  a  narrow  zone 
of  these  stars  would  be  a  work  of  value. 

The  present  thesis  contains  the  results  of  a  part  of  this 
work,  the  mean  declinations  of  136  of  these  stars,  reduced 
to  the  epoch  1912.0,  being  here  included.  It  is  hoped  that 
it  will  be  possible  to  continue  these  observations  until  the 
entire  zone  has  been  twice  passed  over,  and  afterward  to 
carry  on  systematic  observations  for  parallax  upon  such 
of  them  as  give  evidence  of  a  considerable  proper  motion. 
If  this  program  is  completed,  the  detailed  figures  of  the  obser- 
vations will  be  hereafter  published  as  one  of  the  volumes  of 
the  Astronomical  Series  of  The  University  of  Pennsylvania. 
Some  six  hours  of  every  clear  night  are  being  at  present 
devoted  to  this  work,  but  a  brief  description  of  the  method 

(3) 


of  observation  and  a  statement  of  the  mean  results  thus  far 
obtained  seem  all  that  it  is  necessary  to  publish  at  this  time, 
while  the  zone  is  still  incomplete. 

THE  INSTRUMENT  AND  THE  METHOD  OF  MAKING  THE 
OBSERVATIONS. 

The  following  results  were  obtained  from  observations  of 
a  portion  of  a  zone  of  stars  lying  within  15'  of  the  zenith  of 
the  Flower  Observatory  of  the  University  of  Pennsylvania. 
The  Observations  were  made  with  the  Wharton  Reflex 
Zenith  Tube.  This  consists  of  an  objective  of  eight  inches 
aperture  supported  on  a  vertical  tube,  withiri  which  there  is 
a  basin  of  mercury  at  a  distance  of  one-half  the  focal  length 
below  the  center  of  the  objective.  The  focus  of  the  objec- 
tive is  thus  in  the  plane  of  the  micrometer  threads,  0.155 
inches  above  the  surface  of  the  objective  itself.  By  means 
of  a  diagonal  reflector,  the  rays  are  next  directed  into  one 
of  two  horizontal  telescopes  which  rest  upon  the  top  of  the 
tube  and  face  east  and  west. 

The  reticle  contains  two  groups  of  three  threads  each 
which  are  placed  parallel  to  the  meridian,  and  a  single, 
movable  thread  at  right  angles  to  these  with  which  the  decli- 
nations are  measured.  A  star  entering  the  field  crosses  the 
second  thread  of  the  first  group  about  thirty  seconds  before 
the  time  of  meridian  passage  and  reaches  the  third  thread 
after  an  interval  of  about  eight  seconds.  A  bisection  of  the 
star's  image  is  carefully  made  with  the  movable  transverse 
thread  at  the  instant  of  its  transit  of  each  of  these  threads. 
The  micrometer  box,  together  with  the  diagonal  reflector, 
is  then  turned  through  an  azimuth  of  180  degrees  and  the 
star  again  observed  as  it  crosses  the  same  two  threads  on 
the  opposite  side  of  the  meridian.  The  four  readings  thus 
obtained  are  recorded  on  the  self-registering  micrometer 
head. 

This  method  of  observing  has  the  advantage  of  eliminating 
entirely  all  errors  of  azimuth  and  collimination.  It  has  also 


been  found  that  the  objective  may  be  kept  so  nearly  level 
that  the  effect  of  any  level  error  is  entirely  inappreciable. 
The  only  correction  that  need  be  applied  to  the  observed 
zenith  distances  is  hence  that  due  to  the  fact  that  the  bisec- 
tions are  made  when  the  stars  are  at  a  short  distance  from 
the  meridian.  It  is  found  that  when  a  star  is  first  observed 
through  the  east  telescope  this  correction  is  0".38  and  that 
when  it  is  first  observed  through  the  west  one  the  correction 
is  0".48.  In  the  former  case  the  observation  is  said  to  be 
"Direct,"  and  in  the  latter,  "Reverse."  The  aim  was  to 
observe  each  star  Direct  and  Reverse  alternately. 

(A  detailed  description  of  the  instrument  may  be  found  in 
the  Publications  of  the  University  of  Pennsylvania,  Astro- 
nomical Series,  Volume  III,  Part,  1.) 

THE   MICROMETER. 

The  value  of  one  revolution  of  the  micrometer  screw  was 
determined  by  turning  the  instrument  90  degrees  in  azimuth, 
so  that  the  movable  thread  was  parallel  to  the  meridian, 
and  observing  the  times  of  transit  of  a  star  as  it  passed 
horizontally  across  the  field.  The  movable  thread  was 
first  placed  near  that  edge  of  the  field  at  which  the  star 
would  first  appear,  the  micrometer  head  being  set  at  an 
even  reading,  and  the  time  of  transit  was  recorded  on  the 
chronograph.  The  thread  was  then  moved  forward  two 
revolutions,  another  transit  was  recorded,  and  this  was 
repeated  throughout  the  field,  26  transits  being  thus  taken 
for  each  star.  From  the  results  of  observations  on  34  stars 
the  value  of  one  revolution  was  found  to  be,— 

R  =  41  ".5430  =fc  ".003 

When  the  final  values  of  the  declinations  were  obtained, 
it  became  evident  that  this  value  was  considerably  too  small 
and  accordingly  its  correction  was  determined  by  a  least 
square  adjustment  based  upon  all  measured  zenith  distances 
which  exceeded  two  revolutions  of  the  screw.  The  resulting 


correction  was  -{-0".075;  when  this  is  applied  we  obtain  the 
following  value  of  one  revolution  of  the  screw,  and  this  was 
employed  throughout  the  following  computation  : 


This  latter  value  agrees  well  with  the  value  (jR  =  41".60), 
employed  by  Professor  C.  L.  Doolittle  in  his  series  of  latitude 
observations. 

THE  OBSERVING  LIST. 

It  was  found  that  all  stars  of  the  8.5  magnitude  or  brighter 
which  lie  within  15  minutes  of  arc  of  the  zenith  could  be 
readily  observed.  The  declination  of  the  zenith  throughout 
the  twenty-four  hours  of.  right  ascension  was  therefore  first 
reduced  to  1855.0,  the  epoch  of  Argelander's  Durchmus- 
terung,  and  all  stars  fulfilling  the  above  conditions  were 
selected  from  this  catalogue  as  an  observing  list.  There  were 
thus  obtained  586  stars.  The  present  list  comprises  that 
portion  extending  from  22  hours  to  5  hours  right  ascension. 
It  was  afterward  found  that  all  of  these  stars  were  also 
included  in  the  two  Astronomische  Gesellschaft  Zones, 
Lund  34°  42'  to  40°  10',  and  Bonn  39°  50'  to  50°  10'. 

The  A.  G.  positions  of  the  selected  stars  were  next  reduced 
to  the  epoch  1912.0  by  the  usual  formulas,  and  from  these 
reduced  positions  the  star  constants*  a',  bf,  c'  and  d'  were 
computed.  With  the  help  of  these,  and  using  the  values  of 
the  Day  Numbers  from  the  American  Ephemeris  and  Nau- 
vical  Almanac,  the  results  of  the  observations  on  each  night 
were  also  reduced  to  the  epoch  1912.0.  The  results  of  obser- 
tation  were  then  compared  with  the  A.  G.  positions  and  from 
this  comparison  the  values  of  the  proper  motions  given  in 
the  following  table  were  determined.  These  are  therefore 
provisional  proper  motions  only,  depending  on  a  comparison 
of  the  A.  G.  positions  with  the  positions  here  obtained  alone. 

For  the  purpose  of  determining  the  declinations  from  the 
observations,  there  was  assumed  for  the  latitude  the  mean 
value,  39°  58'  2".l 


This  is  the  mean  result  obtained  by  Professor  C.  L.  Doo- 
little  from  observations  extending  over  a  period  of  fifteen 
years. 

THE   FINAL  RESULTS. 

The  final  results  of  the  work  are  stated  in  the  following 
tables.  The  first  three  columns  contain  the  reference  num- 
bers, the  A.  G.  numbers,  and  the  A.  G.  magnitudes  respec- 
tively; the  fourth  column  contains  the  epoch  of  the  present 
observations,  the  fifth  column  contains  the  mean  declina- 
tions as  derived  from  the  observations  and  the  sixth  column 
states  the  residuals  determined  by  subtracting  from  these 
positions  the  reduced  A.  G.  results.  It  is  from  these  that  the 
several  proper  motions  are  computed,  and  the  results  of 
this  computation  are  given  in  the  seventh  column.  The  last 
column  states  the  number  of  nights  on  which  each  star  was 
observed. 


Star     A.  G. 
No.       No. 


Mean 

A.  G.    Epoch 
Mag.     1912.0 


Final  Mean 
Observed 
for  1912.0 


Observed 
A?G. 


1  10568  7.7  0.80 

2  10624  6.2  0.80 

3  10668  8.0  0.81 

4  10723  7.2  0.81 


40     2  51.38 

-0.21 

-0.005 

3 

40   13  23.21 

+  1.95 

+0.050 

6 

40     6  35.26 

-1.48 

-0.038 

7 

40     9  44.96 

-1.70 

-0.044 

7 

5 

10770 

8.9 

0 

,79 

39 

55 

41 

.26 

-0 

.53 

-0.014 

6 

10803 

7.0 

0. 

84 

40 

8 

30 

.55 

-1. 

03 

-0.027 

7 

10818 

6.8 

0. 

82 

40 

12 

44 

.68 

+  2 

.25 

-4-0.058 

8 

10831 

5.7 

0. 

84 

39 

45 

56 

.05 

+0 

,54 

+0.014 

9 

10905 

7.7 

0 

,81 

40 

3 

0 

.11 

-2 

.30 

-0.059 

10 

10928 

7".  8 

0 

.84 

39 

47 

55 

.16 

+  1 

.83 

+0.047 

11 

10950 

5.8 

0.80 

39 

54  27 

,44 

+  1 

.29 

+o 

.033 

3 

12 

11131 

8.2 

0.81 

39 

57  23. 

45 

—  0 

.45 

-0. 

012 

8 

13 

11166 

7.9 

0.81 

39 

45  3. 

35 

-0 

06 

-0, 

002 

8 

14 

11188 

6.9 

0.81 

39 

54  24, 

,85 

-3 

.65 

-0. 

094 

8 

15 

11243 

8.9 

0.81 

40 

2  8. 

81 

-0. 

13 

-0. 

003 

8 

16 

11262 

8.0 

0.82 

40 

0  0. 

21 

2 

04 

-0. 

053 

6 

Star 
No. 

A.  G. 

No. 

A.  G. 

Mag. 

Mean 
Epoch 
1912.0 

Final  Mean 
Observed 
for  1912.0 

Observed 
A.  G.                  / 

n 

_|_ 

o         /            n 

" 

17 

11288 

7. 

4 

0. 

83 

40     4     5  .  94 

-2. 

42 

-0 

.063 

5 

18 

11294 

8. 

4 

o. 

82 

39  49  37.96 

+o. 

89 

+0 

.023 

4 

19 

11304 

9. 

0 

0. 

84 

39  49   11.20 

-1. 

21 

-0 

.031 

5 

20 

11347 

7. 

1 

0. 

82 

39  42  39.53 

-1. 

61 

-0 

.041 

10 

21 

11383 

7. 

7 

0. 

82 

40     6  45.78 

+0. 

91 

+0 

,024 

9 

22 

11426 

8. 

4 

0. 

83 

39  55  21.36 

-1. 

35 

-0. 

035 

6 

23 

11448 

6. 

7 

0. 

81 

x  39  55  42.90 

-0. 

74 

-0. 

019 

6 

24 

11 

8. 

8 

0. 

85 

40     6     5.93 

-0. 

79 

-0. 

020 

4 

25 

17 

7. 

2 

0. 

86 

40     0   17.18 

—  1. 

19 

-0. 

031 

4 

26 

21 

8. 

7 

0. 

85 

40     8  40.12 

+1. 

35 

+0. 

035 

'4 

27 

30 

8. 

9 

0. 

83 

40     5   14.01 

-3. 

86 

-0. 

099 

3 

28 

36 

7. 

8 

0. 

87 

39  54  32.83 

-1. 

85 

-0. 

048 

5 

29 

58 

8. 

2 

0.84 

39  55  50.62 

-0. 

85 

-0 

,022 

5 

30 

113 

8. 

8 

0. 

84 

40   12  25.97 

-1. 

31 

-0 

034 

9 

'31 

150 

8. 

,4 

0. 

84 

40     1  54.21 

-0. 

10 

-0 

003 

9 

32 

215 

8, 

,5 

0. 

83 

39  57  57.09 

+0. 

01 

+  0 

000 

6 

33 

234 

7, 

5 

0. 

86 

39  50  53.24 

-0. 

35 

—  0 

,009 

5 

34 

241 

8 

.7 

0, 

86 

39  57   14.30 

-0. 

11 

-0 

.003 

4 

35 

260 

7 

.5 

0, 

,84 

39  43   12.50 

-15. 

02 

-0 

.387 

5 

36 

270 

7 

,3 

0, 

,85 

40   12  25.27 

-2. 

84 

-0 

.073 

5 

37 

280 

8 

.6 

0 

,87 

39  55   12.23 

-1. 

29 

-0 

.033 

3 

38 

285 

7 

.9 

0 

,88 

39  57     8.94 

-1. 

31 

-0 

.034 

3 

39 

286 

8 

.7 

0 

,87 

40   12   15.83 

+  1. 

50 

+  0 

.031 

4 

40 

287 

6 

.8 

0 

,92 

40   11   53.97 

+0. 

73 

+0 

.019 

3 

41 

294 

8 

.5 

0 

.89 

39  46   12.66 

-2. 

40 

-0 

.062 

4 

42 

298 

8 

.8 

0 

.89 

39  56  38.90 

-1. 

97 

-0 

.051 

5 

43 

315 

8 

.9 

0 

.84 

39  49   12.25 

-0. 

19 

-0 

.005 

6 

44 

340 

6 

.9 

o 

.87 

39  45  56.25 

-0. 

06 

-0 

.002 

8 

45 

365 

8 

.2 

o 

.86 

39  54  21.28 

-0. 

83 

-0 

.021 

5 

46 

375 

8 

.7 

0 

.89 

40     4  24.35 

+  0. 

31 

+  0 

.008 

5 

46' 

381 

9 

.0 

0 

.88 

40     2  45.79 

-2. 

07 

-0 

.053 

3 

47 

468 

8 

.6 

1 

.00 

40   11  24.03 

-2. 

59 

-0 

.067 

1 

48 

487 

8 

.6 

1 

.00 

39  59  32.17 

-3. 

55 

-0 

.091 

1 

49 

488 

8 

.9 

0 

.85 

40  10  27.14 

-3. 

10 

-0 

.080 

10 

50 

531 

8 

.2 

0 

.87 

40   11     4.47 

-0. 

77 

-0 

.020 

9 

51 

548 

9 

.0 

0 

.87 

39  45  39.57 

-1. 

08 

-0 

.028 

6 

52 

577 

7 

.7 

0 

.86 

40     9     2.19 

+0.47 

+  0 

.012 

10 

Star 

No. 

A.  G. 

No. 

A.G. 

Mag. 

Mean 
Epoch 
1912.0 

Final  Mean 
Observed 
fcr  1912.0 

Observed 
A.  G.       f/ 

n 

_j_ 

o 

/   a        a 

53 

602 

8.3 

0.87 

39 

51  17 

.94 

-1 

.67 

-0 

.043 

6 

54 

611 

8.6 

0.89 

39 

53  17 

.58 

+  1 

.77 

+0 

.046 

4 

55 

621 

6.1 

0.86 

39 

52  47 

.09 

+  0 

.06 

+  0 

.002 

6 

56 

646 

8.4 

0.85 

39 

44  41 

.84 

_2 

.36 

-0 

.061 

10 

57 

710 

8.0 

0.86 

39 

50  5 

.26 

-0 

.50 

-0 

.013 

5 

58 

736 

5.1 

0.86 

40 

7  54 

.85 

+  0 

.08 

+0.003 

4 

59 

752 

6.8 

0.85 

39 

55  59 

.63 

-1 

.24 

—  0 

.032 

7 

60 

802 

8.6 

0.87 

40 

1  42 

.40 

-0 

.59 

-0 

.015 

6 

61 

827 

8.2 

0.88 

40 

11  17 

.27 

-0 

.99 

-0 

.026 

5 

62 

836 

8.3 

0.85 

39 

44  15 

.03 

+0.03 

+  0 

,001 

5 

63 

847 

7.3 

0.92 

40 

13  25 

.40 

+0 

.15 

+  0 

.004 

4 

64 

848 

8.2 

0.89 

39 

51  13 

.60 

i 

.88 

-0, 

048 

4 

65 

861 

8.9 

0.86 

40 

0  50 

.92 

—  0 

.69 

-0. 

018 

3 

-  66 

916 

7.9 

0.85 

40 

8  16 

.26 

+  2 

.49 

+  0. 

064 

8 

67 

980 

8.6 

0.85 

40 

10  43 

.47 

+  0 

.57 

+0. 

015 

11 

68 

1016 

8.3 

0.86 

40 

6  20 

.46 

+  0, 

65 

+  0. 

017 

8 

69 

1043 

7.9 

0.86 

39 

50  36 

.25 

+  0.81 

+  0. 

021 

5 

70 

1052 

7.2 

0.87 

40 

5  50 

.26 

-2. 

,73 

-0. 

070 

6 

71 

1102 

7.6 

0.85 

40 

8  33 

,48 

-2. 

42 

-0. 

060 

5 

72 

1111 

7.8 

0.89 

39 

52  21 

.50 

-1. 

70 

-0. 

044 

7 

73 

1122 

8.4 

0.85 

40 

3  42 

53 

-0. 

84 

-0. 

022 

7 

74 

1215 

7.4 

0.89 

39 

46  38. 

22 

+  0. 

20 

+0. 

005 

7 

75 

1232 

7.3 

0.87 

39 

53  0. 

73 

-1. 

05 

-0. 

027 

7 

76 

1248 

8.4 

0.88 

39 

54  22. 

82 

-0. 

92 

-0. 

024 

7 

71 

1251 

7.9 

0.90 

40 

12  40. 

92 

—  1. 

18 

-0. 

030 

7 

78 

1265 

7.1 

0.91 

39 

49  13. 

74 

-1. 

83 

-0. 

047 

4 

79 

1330 

9.0 

0.89 

39 

53  30.08 

+4. 

89 

+  0. 

126 

6 

80 

1339 

5.5 

0.91 

39 

49  19. 

11 

-5. 

48 

-0. 

141 

3 

81 

1346 

7.6 

0.90 

39 

53  9. 

82 

-1. 

08 

-0. 

028 

3 

82 

1422 

8.0 

0.88 

40 

6  48. 

89 

+  0. 

63 

+0. 

016 

7 

83 

1450 

8.2 

0.87 

39 

46  27. 

72 

-0. 

22 

-0. 

006 

9 

84 

1506 

8.4 

0.86 

39 

53  50. 

22 

-0. 

63 

-0. 

016 

6 

85 

1523 

8.9 

0.90 

39 

56  18. 

59 

-0. 

93 

-0. 

024 

6 

10  ' 


Star 
No. 

A.  G. 

No. 

A.  G. 

Mag. 

Mean 
Epoch 
1912.0 

Final  Mean 
Observed 
for  1912.0 

Observed 

n 

_j_ 

0 

/   if        if 

86 

1543 

7.0 

0.88 

40 

4  6. 

87 

+o. 

02 

+  0. 

001 

5 

87 

1551 

8.0 

0.88 

40 

0  55. 

56 

-0. 

87 

-0, 

022 

6 

88 

1572 

6.9 

0.87 

39 

56  56. 

18 

—  1. 

74 

-0, 

045 

8 

89 

1595 

8.0 

0.89 

39 

51  46, 

,83 

-0. 

42 

-0 

,011 

6 

90 

1601 

8.0 

0.87 

39 

44  48, 

79 

+  0. 

39 

+0 

010 

5 

91 

1658 

8.4 

0.88 

39 

49  24 

.59 

-1. 

30 

-0 

.033 

4 

92 

1668 

8.4 

0.88 

39 

52  21 

.  11 

—  1. 

74 

-0 

.045. 

4 

93 

1669 

7.0 

0.91 

39 

47  25 

.35 

-1. 

01 

-0 

.026 

5 

94 

1690 

7.1 

0.87 

40 

9  35, 

61 

+  1. 

30 

+  0 

,033 

9 

95 

1740 

8.3 

0.87 

39 

51  9. 

61 

+  0. 

11 

+  0 

.003 

5 

96 

1750 

7.2 

0.91 

39 

43  54, 

,21 

-1. 

19 

-0 

031 

7 

97 

1753 

7.2 

0.90 

39 

54  39, 

10 

+0. 

18 

+  0 

005 

5 

98 

1770 

8.2 

0.89 

40 

8  57 

,25 

—  1. 

53 

-0, 

.039 

5 

99 

1785 

6.8 

0.87 

39 

51  56, 

.90 

-1. 

38 

-0 

,036 

5 

100 

1793 

7.3 

0.90 

39 

52  52 

.65 

-0. 

75 

-0 

,019 

6 

101 

1850 

7.3 

0.88 

40 

0  37 

.21 

+o. 

37 

+o 

.010 

8 

102 

1874 

7.0 

0.88 

39 

47  56 

.99 

-0. 

90 

-0 

.023 

8 

103 

1934 

7.2 

0.88 

39 

48  7 

.71 

-1. 

19 

-0 

.031 

7 

104 

1973 

8.5 

0.92 

39 

59  38 

69 

-1. 

50 

-0 

,039 

4 

105 

1978 

7.6 

0.92 

40 

6  6 

,55 

+0. 

76 

+o 

.020 

4 

106 

1979 

8.8 

0.91 

39 

51  18 

56 

-2. 

03 

-0 

.052 

5 

107 

2019 

3.3 

0.90 

39 

45  22 

.72 

-1. 

50 

-0 

.039 

7 

108 

2040 

7.4 

0.89 

39 

45  47 

96 

+  0. 

49 

+  0 

,013 

3 

109 

2047 

8.4 

0.92 

39 

57  10 

.51 

-0. 

93 

-0 

.024 

3 

110 

2054 

7.0 

0.92 

39 

50  51 

93 

-3. 

06 

-0 

,079 

5 

111 

2062 

7.3 

0.92 

39 

44  30 

,38 

-1. 

70 

-0 

,044 

3 

112 

2098 

7.7 

0.90 

40 

3  42 

,74 

-0. 

16 

-0 

,004 

10 

113 

2127 

7.5 

0.90 

39 

55  50 

,34 

•? 

80 

-0. 

,098 

8 

114 

2158 

7.7 

0.91 

40 

8  1 

,05 

-0. 

63 

-0 

016 

5 

115 

2147 

8.5 

0.90 

40 

2  13, 

76 

-0. 

62 

-0, 

016 

5 

116 

2202 

8.0 

0.89 

39 

42  8, 

21 

—  1  . 

63 

-0, 

042 

7 

117 

2182 

7.8 

0.90 

39 

48  26 

.70 

-0. 

94 

-0 

024 

9 

118 

2244 

8.3 

0.91 

40 

6  2 

,08 

-1. 

89 

-0 

049 

8 

II 


Mean  Final  Mean  Observed 

Star        A.  G.        A.  G.    Epoch  Observed 

No.        No.          Mag.     1912.0  for  1912.0  A.  G. 


119 

2218 

7.0 

0.91 

39 

43  42 

.10 

-1 

.64 

-0. 

042 

8 

120 

2270 

6.9 

0.95 

39 

49  10 

.27 

—  1 

86 

-0. 

048 

4 

121 

2264 

8.0 

0.89 

39 

57  16 

.52 

—  1 

,21 

-0. 

031 

3 

122 

2305 

8.5 

0.91 

40 

7  14 

.15 

-1 

.57 

-0. 

040 

6 

123 

2274 

8.3 

0.95 

39 

44  9 

.94 

-1 

.95 

-0. 

050 

3 

124 

2357 

6.1 

0.93 

40 

9  11 

.41 

-2 

.19 

-0. 

056 

4 

125 

2340 

8.3 

0.91 

39 

42  41 

.00 

-3 

.19 

-0 

.082 

7 

126 

2399 

8.0 

0.92 

39 

51  38 

,40 

+  0, 

08 

+0 

.002 

4 

127 

2363 

8.7 

0.95 

40 

4  28 

.15  • 

-0 

.29 

-0 

.007 

4 

128 

2417 

8.3 

0.91 

40 

1  43 

.85 

2 

46 

-0 

.063 

2 

129 

2410 

8.3 

0.95 

39 

45  43 

.53 

-1. 

56 

-0 

.040 

4 

130 

2435 

8.7 

0.94 

40 

6  52 

37 

+  0. 

63 

+0 

.016 

3 

131  2431  6.9  0.95 

132  2459  7.8  0.94 

133  2452  7.0  0.94 

134  2486  8.4  0.94 

135  2478  8.0  0.95 


39  55  20.44 

39  49  47.45 

40  6  2.78 
39  50  43.80 
39  57  2. 19 


-4.31 
-1.52 
+  0.20 
-1.42 
-1.16 


-0.112  4 

-0.039  3 

+0.005  3 

-0.036  3 

-0.030  4 


OTHER  CATALOGUE   POSITIONS. 

The  various  available  star  catalogues  were  next  examined 
for  observations  of  these  stars,  with  the  result  that  of  eight- 
een of  them  it  was  found  that  positions  had  been  determined 
elsewhere.  The  eighteen  stars,  together  with  the  names  of 
the  catalogues  in  which  they  are  to  be  found,  and  the  several 
determinations  of  the  proper  motions  are  stated  in  the 
following  table.  The  abbreviation  G.  C.  S.  here  signifies,— 
"A  New  Reduction  of  Groombridge  Circumpolar  Stars," 
The  Royal  Observatory,  Greenwich,  1905. 


Number.    Catalogue. 

Star  Name  or  No. 

4         G.  C.  S. 

Grom.  3803 

12  Lacertag 

8          B.  A.  C. 

7975 

Gr.  9  yr.,  1872 

.2135 

Brad. 

3002 

G.  C.  S. 

Groom.  3856 

Mag. 


5.5 
6.0 


-0.035 

-0.01 
-0.02 

+  0.018 


12 


^umbei 

•.    Catalogue. 

Star  Name  or  No. 

Mag. 

ft' 

10 

G.  C.  S. 

Groom,  3908 

+  0.015 

11 

Gr.  10  yr.,  Glas. 

3838 

G.  C.  S. 

Grom.  3919 

6.1 

+  0.051 

B.  A.  C. 

7984 

6.0 

Gr.  9yr.,  1872 

6.0 

+  0.  114 

39 

G.  C.  S. 

Grom.  131 

-0.026 

40 

G.  C.  S. 

Grom.  133 

-0.007 

44 

G.  C.  S. 

Grom.  162 

+  0.043 

45 

G.  C.  S. 

Grom.  178 

-0.027 

52 

G.  C.  S. 

Grom.  302 

+  0.009 

53 

G.  C.  S. 

Grom.  308 

-0.005 

55 

G.  C.  S. 

Grom.  313 

-0.019 

58 

Porter,  4280  stars. 

317 

5.5 

G.  C.  S. 

Grom.  372 

-0.029 

Gr.  10  yr.,  Glas. 

236 

-0.015 

Gr.  7  yr.,  1864 

227 

5.0 

-0.209 

Boss 

369 

5.0 

-0.025 

B.  A.  C. 

502 

-0.09 

Gr.  9yr.,  1872 

154 

5.0 

-0.09 

T  Andromedae 

59 

G.  S.  C. 

Grom.  368 

+  0.014 

63 

G.  C.  S. 

Grom.  400 

+0.013 

80 

G.  C.  S. 

Grom.  542 

-0.191 

Gr.  10  yr.,  Glas. 

401 

5.0 

-0.  179 

Gr.  7  yr.,  1864 

353 

5.0 

-0.348 

Porter,  2030  stars 

180 

5.5 

-0.182 

B.  A.  C. 

821 

5.5 

-0.  160 

Boss 

610 

5.1 

-0.191 

94 

Gr.  10  yr.,  Glas. 

492 

W.  B. 

*IIJ    157 

6.8 

2  369 

B.  G.  C. 

1633 

107 

£  Persei 

Gr.  10  yr.,  Glas. 

610 

3.0 

-0.016 

B.  A.  C. 

1219 

3.5 

-0.030 

Boss 

910 

2.9 

-0.029 

Gr.  12  yr.,  1847 

336 

3.4 

-0.030 

Gr.  9  yr.,  1872 

361 

3.5 

-0.040 

G.  C.  S. 

Groom.  .765 

-0.027 

Porter,  2000  stars. 


463 


145 


*  Companion  star  preceding,  in  A.  G. 


CONCLUSION. 

The  results  of  the  observations  thus  far  made,  clearly 
indicate  a  considerable  proper  motion  in  several  of  these 
stars.  This  is  especially  marked  in  numbers  14,  27,  35,  48, 
49,  79,  80,  113,  125,  and  131.  The  large  value  from  five 
accordant  observations  of  number  35  is  especially  notable. 
If  these  values  are  confirmed  upon  the  repetition  of  the  obser- 
vation of  this  zone,  it  appears  that  the  list  will  furnish  several 
stars  upon  which  parallax  observations  can  be  undertaken 
with  considerable  prospect  of  success. 


Gay] 
M 

Syraci 


Anders  on*  |E'«   5. 

at  ion  of 
mean  declinations 


stars 


the 


A 


